Disulfides in reversal photographic processes

ABSTRACT

STABLE EARLY-STAGE PROCESSING SOLUTIONS, E.G., PREBATHS, CONTAINING BIS(LOWERALKYLCARBONAMIDOPHENYL) DISULFIDES, E.G., BIS(O-(N-ETHYL)ACETAMIDOPHENYL)DISULFIDE, PROMOTE DESIRABLE DYE DENSITY IN HIGHLIGHT AREAS DURING COLOR DEVELOPMENT IN REVERSAL COLOR PROCESSING.

United States Patent 15cc 3,597,207 Patented Aug. 3, 1971 3,597,207 DISULFIDES IN REVERSAL PHOTOGRAPHIC PROCESSES Arthur D. Kuh, Penfield, and Charleton C. Bard, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y. No Drawing. Filed Apr. 1, 1969, Set. N0. 812,355 Int. Cl. G03c 5/24, 5/50 US. Cl. 96-65 26 Claims ABSTRACT OF THE DISCLOSURE Stable early-stage processing solutions, e.g., prebaths, containing bis(loweralkylcarbonamidophenyl) disulfides, e.g., bis [o-(N-ethyl) acetamidophenyl] disulfide, promote desirable dye density in highlight areas during color development in reversal color processing.

This invention relates to color photography. In one of its aspects this invention relates to methods and materials for use in reversal color processing. In another of its aspects this invention relates to methods and materials which can be employed in early stages of reversal color processing, especially of multilayer color photographic elements having color forming couplers incorporated therein.

Reversal processing of multilayer, incorporated coupler, color photographic materials normally involves: predevelopment treatment of an imagewise exposed element with compositions, e.g., containing hardening agents, to prepare the emulsions for the temperature conditions, etc. employed in the remaining steps of the process; black and white development; chemical or physical fogging of undeveloped silver halide and color development; con- 9 version of developed silver to ionic silver; removal of the ionic silver; and treatment with a composition which will inhibit fading of the dyes produced on color development.

The ever-increasing demand for high-quality and more rapid customer service has stimulated efforts to increase the rate at which photographic materials can be processed by such methods to produce high-quality photographic color reproductions. These efforts have included increasing the temperature of the various processing steps, modification of the components and concentrations of various processing compositions, etc. One such modification is described in US. Pat. No. 3,342,596 by James L. Graham. This patent discloses a series of compounds which can be beneficially utilized in predevelopment treatments.

The compounds disclosed in the Graham patent when used in the early stages of reversal processing have been found to promote dye formation in the highlight areas in the color development step with minimal increase in base density. This surprising result, heretofore considered substantially unique to such compounds, is believed by theorists to be due to a unique antifoggant action which results in a disproportionate inhibition of black and white development in areas of the film which are ultimately the highlight areas. The result has been effectively employed in efforts to provide colored photographs having more pleasing contrast, softer shadows in highlight areas (the toe region).

Some success has been associated with the use of such compounds, especially in high volume processing operations which consume processing solutions at a rapid rate. However, it has been found that these compounds are somewhat unstable when stored for long periods of time in solution with other components of predevelopment treatment compositions, e.g., prebaths, and are readily oxidized when contacted with air. Any such reactions, which alter the photographic activity, result in difficulty for the processing operations which use small volumes of solution over extended periods of time. The alteration of photographic activity under storage conditions also makes it difficult or impractical for a manufacturer to prepare and market ready-to-use solutions or kits containing aqueous solutions containing such compounds despite a large demand for such items.

Therefore, extensive research has been undertaken in an effort to prepare predevelopment treatment compositions for color reversal processes which compositions employ stable compounds that promote a comparatively high increase in dye yield in highlight areas.

We have found that bis(loweralkylcarbonamidophenyl) disulfides are surprisingly stable and effective when used in early stages of reversal color processing and ultimately promote increased dye formation in highlight areas with minimal increase in base density of the color photographic product.

According to one advantageous embodiment of the present invention, compounds having the formula:

wherein R and R are independently selected lower alkyl groups having 1-6 C atoms desirably having l-3 C atoms (advantageously methyl); R and R are independently selected alkyl groups having 1-6 C atoms, desirably 1-3 C atoms (advantageously ethyl) wherein the sum of the carbon atoms in groups R plus R and the sum of R plus R are each less than 8; and Z and Z are independently selected phenylene groups including unsubstituted phenylene moieties or phenylene moieties containing innocuous substituents, e.g., methyl, etc., are utilized in color reversal processing in stable predevelopment treatment solutions (i.e., treatment prior to conversion of exposed silver halide grains to silver) to effectively and disproportionately promote dye formation in highlight areas. In an especially advantageous embodiment of the present invention the selected compounds have the formula:

wherein R -R are as given above. In a preferred embodiwherein R -R are independently selected lower alkyl groups each having from 1-3 carbon atoms, especially wherein R and R each equal methyl and/or R and R each equal ethyl groups as in bis-[o-(N-ethyl)acetamidophenyl1disulfide. The bis (loweralkylcarbona midophenyl) disulfides useful in the successful practice of the present invention may be prepared according to the methods described in Elderfield, Heterocyclic Compounds, John A. Wiley & Son, 1957 at page 648, or alternatively using the methods described in the paper by W. H. Mills, L. M. Clark, and .T. A. Heschlimann reported at J. Chem. Soc., vol. 123; pp. 2353-70, 1923.

The bis(loweralkylcarbonamidophenyl) disulfides are especially effective in methods for reversal color processing of multilayer, incorporated coupler, color photographic elements which methods include the following steps:

(a) Treating an exposed element of the type described having a gelatinous binder in a prehardening composition to prepare the element for subsequent processing conditions (e.g., prehardening);

(b) Treating the element in a neutralizing bath whereby the effect of the treating in (a) is controlled (or more simply, neutralizing);

(c) Treating the element from (b) to convert exposed silver halide to metallic silver (black and white develops);

(d) Treating the element from (c) in an acidic composition to stop development (stopping);

(e) Treating the element from (d) with a composition containing chemical fogging agent and phenylenediamine developing agent to fog unexposed silver halide and develop dye in areas containing said unexposed silver halide (fogging and color developing);

(f) Treating the color developed element in an acidic composition (stopping);

(g) Treating said color developed element to convert metallic silver to ionic silver (silver bleaching);

(h) Treating the silver bleached material to remove ionic silver from the element (fixing); and

(i) Treating the fixed element to render the dyes therein more stable (stabilizing).

Washing with demineralized water in such processes is usually recommended between ((1) and (e), between (f) and (.g), and between (h) and (i). Times and temperatures for such processes may be varied widely but normally is conducted at above room temperature. When the treating compositions are aqueous solutions through which the element passes, it is normally advantageous to utilize temperatures and dwell times as follows: preharden, 29.5 C. for 3 minutes; neutralize, 28-31 C. for 1 minute; develop, 29.5 C. for about 7 minutes; first stop, 28-31 C. for 2 minutes; wash, 27-32 C. for 4 minutes; fog and color develop, 283l C. for 9 minutes; second stop, 2831 C. for 3 minutes; wash, 27-32 C. for 3 minutes; bleach, 28-3l C. for 5 minutes; fix, 283l C. for 6 minutes; wash, 2732 C. for 6 minutes; stabilize, 28-31 C. for 1 minute; and dry at not over 43 C.

The bis(loweralkylcarbonamidophenyl) disulfides according to the present invention can be utilized in the treating steps (a), (b), and (c), (i.e., in predevelopment treatment compositions, a phrase which is intended to include any treatment composition which includes components which affect the binder or silver halide grain prior to conversion of exposed silver halide to metallic silver, i.e., prior to or simultaneously with black and white developing). Such compositions include prehardening baths, e.g., containing formaldehyde; neutralizing baths, e.g., containing hydroxylamine; and black and white developers, e.g., containing p-methylaminophenol sulfate and hydroquinone.

The disulfide compounds are advantageously included in aqueous predevelopment treatment solutions in concentrations of up to about 100 mg. per liter of solution, desirably from about 1 mg. to about 50 mg. per liter, with concentrations of about 10 mg. per liter being especially useful. However, higher concentrations are useful in, for example, packaged solutions where it is normally advantageous to minimize shipping, etc. costs by packaging the solutions as concentrates which are eventually diluted for use.

The bis(loweralkylcarbonamidophenyl) disulfides are particularly useful as addenda to aqueous prebath solutions, i.e., prehardener and neutralizer compositions, in the concentrations mentioned. Prebath compositions including these disulfides show surprising stability even when exposed to air for relatively long periods of time and even though the disulfide is in solution with known gelatin hardening agents, for example, formaldehyde, succinaldehyde, etc. or with hydroxylamine sulfate. The concentration of the various other agents, e.g., aldehyde hydroxylamine, can vary considerably with the particular choice of hardening agent, hardness desired, temperature selected, etc.

The following examples are intended to illustrate our invention and! or advantages thereof.

EXAMPLE 1 A multilayer film having a transparent support and respectively coated thereon at least a red sensitive silver bromoiodide gelatin emulsion containing cyan-forming color coupler, a green sensitive silver bromoiodide gelatinous emulsion layer containing a magenta dye-forming color coupler, a yellow filter layer, and a blue sensitive silver bromoiodide gelatinous emulsion layer containing a yellow dye-forming color coupler is exposed to a light image. The imagewise exposed element is then treated in the following solutions all at 86 F.

Prehardener 3 minutes 12 seconds immersion in the composition:

Water: 700.0 ml.

Glycine: 1.0 g.

Disodium succinaldehyde bisulfite: 6.5 g. Sodium sulfate, anhydrous: 75.0 g. Magnesium sulfate (7H O): 257.0 g. Sodium bromide, anhydrous: 2.0 g. Sodium acetate, anhydrous: 15.0 g. Glacial acetic acid: 3.0 ml. Formaldehyde (37.5%): 27.0 ml. Water to 1 liter pH at F.: 4.80

Aldehyde neutralizer 1 minute 36 seconds immersion of prehardened film in the composition:

Water: 800.0 ml.

Hydroxylamine sulfate: 18.0 g.

Sodium bromide, anhydrous: 17.0 g.

Glacial acetic acid: 10.0 ml.

Sodium hydroxide: 6.8 g.

Sodium sulfate: 50.0 g.

Bis [o-(N-ethylacetamido)phenyl]-disulfide: 10.0 mg. Water to 1 liter pH at 80 F.: 5.10:0.2

Black and white development The film is developed about 6 minutes in a black-andwhite developer having the following composition:

Water, 90 F. (32 C.): 1.0 liter Sodium hexametaphosphate: 2.0 g. N-methyl-p-aminophenol sulfate: 6.0 g.

Sodium sulfite, desiccated: 50.0 g.

Hydroquinone: 6.0 g.

Sodium carbonate, monohydrate: 35.0 g.

Potassium bromide: 2.0 g.

Sodium thiocyanate: 1.5 g.

6.5% solution of 6-nitro-benzimidazole nitrate: cc. 0.1% solution of potassium iodide: 10.0 cc.

EXAMPLE 2 The procedure according to Example 1 is followed except that the light sensitive material is exposed to a 21-step, neutral step wedge. The dye density of the processed film is then plotted in the conventional manner, i.e., considering dye density and log E. The processed film has the desired dye density in the toe area of the curve.

EXAMPLE 3 The procedure according to Example 2 is utilized except that for the neutralizer of Example 2 is substituted an aged (over 3 weeks in an open container at room temperature), but otherwise identical, neutralizer. Results substantially identical to Example 2 are noted.

EXAMPLE 4 The procedure according to Example 2 is followed except that for the prehardener of Example 2 is substituted a fresh prehardener prepared by combining the following in the manner indicated:

and the disulfide compound is deleted from the neutralizer of Example 2. Results substantially identical to those of Example 2 are noted.

EXAMPLE 5 The procedure according to Example 4 is followed except that for the prehardener of Example 4 is substi tuted an aged (3 weeks in an open container at room temperature), but otherwise identical, prehardner. Results substantially identical to Example 4 are noted.

EXAMPLE 6 (comparative) The procedure according to Example 4 is followed except that the prehardener contains bis[o-(N-methyl) formamidophenylJdisulfide in lieu of the disulfide of Example 4. With a fresh prehardener, results substantially identical to those of Example 4 are noted.

EXAMPLE 7 (comparative) The procedure according to Example 6 is followed except that an aged (3 weeks in an open container at room temperature), but otherwise identical, prehardener is utilized in lieu of that of Example 6. The processed element has substantially decreased dye density in the toe areas as compared to either the processed element of Example 6 or Example 5:

EXAMPLE 8 (comparative) The procedure according to Example 2 is followed except that bis[o (N methyl)formamidophenyl]disulfide is substituted for the disulfide used in the neutralizer of Example 2. With a fresh neutralizer, results substantially identical to those of Exemple 2 are obtained.

EXAMPLE 9 (comparative) The procedure according to Example 8 is followed except that an aged (3 weeks in an open container at room temperature), but otherwise identical, neutralizer is utilized in lieu of that of Example 8. The processed element has substantially decreased dye density in the toe areas as compared to Example 8 or Example 5.

EXAMPLE 10 The procedure according to Example 2 is followed except that the disulfide compound is deleted from the neutralizer, and to the black and white developer is added a sufficient amount of the same disulfide compound to make a concentration of about mg. disulfide per liter of developer. Results similar to those of Example 2 are obtained.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

We claim:

1. In the method for reversal color processing of imagewise exposed, multilayer, incorporated coupler, silver halide-gelatin emulsion color photographic elements, said method comprising:

(a) contacting the emulsion with predevelopment treatment compositions to prepare the element for remaining' processing steps;

(b) developing to convert exposed silver halide to metallic silver;

(c) contacting with an acidic composition;

(d) fogging and color developing;

(e) silver bleaching;

(f) fixing; and

(g) stabilizing; the improvement which comprises incorporating a his (loweralkylcarbonamidophenyl)disulfide into at least one of said predevelopment treatment compositions.

2. The invention according to claim 1 and wherein the predevelopment treatment composition that contains the bis(loweralkylcarbonamidophenyl)disulfide is a prehardener which also contains formaldehyde.

3. The invention according to claim 1 and wherein the predevelopment treatment composition that contains said disulfide is a prehardener that contains from about 1 to about mg. of said disulfide per liter of solution.

4. The invention according to claim 1 and wherein the predeveolpment treatment composition that contains said disulfide is a neutralizer.

5. The invention according to claim 1 and wherein the predevelopment treatment composition that contains said disulfide is an aqueous neutralizer that contains the dissolved residues from hydroxylamine sulfate and about 1 to about 50 mg. of said disulfide per liter.

6. The invention according to claim 1 and wherein said disulfide is bis [0- (N-ethyl acetamidophenyl] disulfide.

7. The invention according to claim 3 and wherein said disulfide is bis[o-(N-ethyl)acetamidophenyl]disulfide.

8. The invention according to claim 5 and wherein said disulfide is bis[o-(N-ethyl)acetamidophenyl]disulfide.

9. In the method for reversal color processing of imagewise exposed multilayer, incorporated coupler, silver halide-gelatin emulsion color photographic elements said method comprising: (a) prehardening; (b) neutralizing; (0) black and white developing; (d) stopping; (e) color developing; (f) stopping; (g) bleaching; (h) fixing; (i) stabilizing and (j) drying; the improvement which comprises accomplishing at least one of steps (a), (b), and (c) with an aqueous solution which contains at least one compound having the formula:

wherein R and R are independently selected lower alkyl groups having 1-6 C atoms; R and R are independently selected alkyl groups having 1-6 C atoms, wherein the sum of the carbon atoms in groups R plus R and the sum of R plus R are each less than 8; and Z and Z are independently selected phenylene groups; in a concentration of about 1 mg. to about 50 mg. per liter of solution.

10. The invention according to claim 9 and wherein R R R and R are independently selected alkyl groups each having 1-3 carbon atoms.

11. The invention according to claim 9 and wherein said disulfide has the formula:

R COIIIR" R IIICOR wherein R R R and R are independently selected lower alkyl groups each having from 1-3 carbon atoms.

12. The invention according to claim 9 and wherein said disulfide is his (N-ethyl) acetamidophenyl] disulfide.

13. In a predevelopment treatment composition for use in treating imagewise exposed multilayer, incorporated coupler, silver halide-gelatin emulsion color photographic elements, said composition comprising an aqueous solution containing one member selected from the class consisting of gelatin hardening agents, neutralizing agents which neutralize said hardening agents, and black and white developing agents, the improvement which comprises incorporating into said composition at least one compound having the formula:

wherein R and R are independently selected lower alkyl groups having 1-6 C atoms; R and R are independently selected alkyl groups having 1-6 C atoms, wherein the sum of the carbon atoms in groups R plus R and the sum of R plus R are each less than 8; and Z and Z are independently selected phenylene groups; in a concentration of about 1 mg. to about 50 mg. per liter of solution.

14. The invention according to claim 13 and wherein selected member is gelatin hardening agent.

15. The invention according to claim 14 and wherein the formaldehyde is included as a hardening agent.

16. The invention according to claim 13 and wherein said disulfide is bis[o-(N-ethyl)acetamidophenyl] disulfide and formaldehyde is included in the solution as a gelatin hardening agent.

17. The invention according to claim 13 and wherein the selected member is neutralizing agents.

18. The invention according to claim 17 and wherein the solution contains the dissolved residues from hydroxylamine sulfate as a selected neutralizing agent.

19. The invention according to claim 13 and wherein said disulfide is bis[o-(N-ethyl)acetamidophenyl] disulfide and the solution contains the dissolved residues from bydroxylamine sulfate as the selected neutralizing agent.

20. A dryer for sheet material comprising, in combination:

a drum structure including a cylinder having a perforated wall;

a pliant porous blanket wrapped around said cylinder;

and a porous cover around said blanket formed without an axial seam and having an outer textured surface for supporting sheet material with a minimum of contact between said cover and said sheet material;

a platen having a polished surface conforming substantially to the outer surface of said drum structure; means for supporting said platen against said outer surface;

means for heating said platen;

means for rotating said drum structure in contact with said platen; and

means for propelling air through said cylinder.

21. A dryer as defined in claim 21 wherein said cover comprises a filament wound in a helix around said blanket.

22. A dryer as defined in claim 21 wherein said filament is a fibrous thread.

23. A dryer as defined in claim 22 wherein said thread is formed of cotton fibers.

24. A dryer as defined in claim 21 wherein said cover is a pile fabric.

25. A dryer as defined in claim 21 wherein said blanket is a felt.

26. A dryer as defined in claim 21 wherein said blanket is formed of an open cellular material.

References Cited UNITED STATES PATENTS 2,453,087 11/1948 Dersch ct a1. 96-56 NORMAN G. TORCHIN, Primary Examiner A. T. SURO PICO, Assistant Examiner US. Cl. X.R. 9656 mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3397.207 Dated Augu t 3, 197

Inventor(s) Arthur D. Kuh and Charleton C. Bard It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 9, "26 Claz'tms should read -l9 Claims-. In columns 7 and 8, claims 20 to 26 should be deleted.

Signed and Scaled this second D3) 0f March 1976 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner njParents and Trademarks 

